81653600 has 108 divisors (see below), whose sum is σ = 231992964. Its totient is φ = 27982080.

The previous prime is 81653599. The next prime is 81653609. The reversal of 81653600 is 635618.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81653609) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 38159 + ... + 40241.

It is an arithmetic number, because the mean of its divisors is an integer number (2148083).

Almost surely, 2^81653600 is an apocalyptic number.

81653600 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81653600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115996482).

81653600 is an abundant number, since it is smaller than the sum of its proper divisors (150339364).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81653600 is a wasteful number, since it uses less digits than its factorization.

81653600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2117 (or 2097 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 81653600 is about 9036.2381553388. The cubic root of 81653600 is about 433.8355256057.

The spelling of 81653600 in words is "eighty-one million, six hundred fifty-three thousand, six hundred".